JP2000250100A - Illuminating device for optical measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illuminator for an optical measuring instrument which is simply constituted, and also capable of easily varying an irradiation angle with reference to an object to be measured. SOLUTION: An irradiation angle varying means 42 for condensing the illuminating light from a light emitting means 41 toward the object to be measured 25 is constituted by installing a simply constituted optical member as a light condensing lens 44. By making the light condensing lens 44 movable along the optical axis of the optical system, the irradiation angle of the illuminating light with reference to the object to be measured 25 is easily varied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination used in an image processing type measuring instrument for measuring the size and shape of an object to be measured from an image of the object to be measured obtained by an optical system and other optical measuring instruments. Related to the device. More specifically, the present invention relates to an improvement in an illumination device that irradiates an object to be measured with illumination light from a direction inclined with respect to an optical axis of an optical system.

[0002]

2. Description of the Related Art An image processing type measuring device for optically enlarging a measurement site of an object to be measured by an enlarging optical system and measuring a size and a shape of the object from an enlarged image, for example, a tool microscope, a projector, In a visual coordinate measuring machine or the like, illumination of the object to be measured plays an extremely important role in obtaining an enlarged image of the object to be measured.

Conventionally, as an illumination method in an image processing type measuring instrument, there has been known a vertical epi-illumination method in which illumination light is applied to an object from almost directly above the object. However, the vertical epi-illumination method is often used when measuring an object having a relatively simple shape, and is used to measure an object having a complicated shape, for example, a step-shaped object having many edges. In measurement, the shadow of the edge may not be clearly depicted on a display device or the like.

In order to solve this problem, the shadow of the edge can be clearly detected by irradiating the object with illumination light from a direction inclined at a predetermined angle with respect to the optical axis of the magnifying optical system. Such a lighting device has been proposed. For example, a parabolic mirror that reflects irradiation light emitted from a fiber illuminating device in parallel with the optical axis in a direction substantially orthogonal to the optical axis of the optical system, and directs the irradiation light reflected by the mirror to the device under test. Conventional example 1 is provided with a ring-shaped mirror for focusing light. In the first conventional example, the irradiation angle of the parabolic mirror with respect to the portion to be measured is changed by adjusting the amount of movement of the parabolic mirror with respect to the illumination device and the relative position of the ring mirror with respect to the optical axis.

Further, a ring-shaped condenser lens for refracting irradiation light emitted from the fiber illuminating device in a direction away from the optical axis of the optical system, and converging the irradiation light refracted by the condenser lens toward the object to be measured. There is a conventional example 2 (Japanese Utility Model Laid-Open No. 7-23208) provided with a ring-shaped reflecting member. In the second conventional example, the ring-shaped reflecting member includes a plurality of petal-shaped mirror pieces which are sequentially arranged in a partially overlapping state on a circumference around the optical axis, and the ends of the mirror pieces open and close. This changes the irradiation angle to the object to be measured.

Further, there is provided a conventional example 3 in which a plurality of LEDs directed to the object to be measured are provided around the optical axis to irradiate light, and the illumination angle is changed by controlling the lighting positions of these LEDs.
There is. In addition, a ring-shaped lens is placed around the optical system,
There is a fourth conventional example in which the light source is moved in the radial direction of the lens above the light source to adjust the angle of light illuminating the object to be measured.

Further, there is a conventional example 5 (Japanese Patent Application Laid-Open No. 8-166514) in which illumination light is obliquely directed toward an object to be measured via a peripheral portion of the objective lens which is distant from the optical axis of the objective lens. Also,
Conventional example 6 includes a reflecting mirror that reflects illumination light emitted from a light source and a fixed Fresnel lens that condenses the illumination light reflected by the mirror toward an object to be measured.

[0008]

In the prior art 1, in order to irradiate the light from the fiber illuminating device with a predetermined set of reflected light by two sets of mirrors, the reflecting surface of each mirror must be formed in a parabolic cross section. . Therefore, there is a problem that high-level reflection surface processing is required and the manufacturing cost is increased. Further, a complicated moving mechanism is required to relatively move both mirrors, which also increases the manufacturing cost. In Conventional Example 2, the ring-shaped reflection member has a complicated structure including a plurality of petal-shaped mirror pieces, and the ring-shaped reflection member is opened and closed by synchronously operating all the mirror pieces. There is a problem that it is difficult to adjust the irradiation light.

In the third conventional example, a large number of LEDs are required to change the irradiation angle, which not only increases the manufacturing cost but also causes inconvenience due to heat generation. Further, in the conventional example 4, since the ring-shaped lens becomes large in order to obtain a large irradiation angle, the change of the irradiation angle is limited. In addition, when ring-shaped fiber illumination is used as the light source, the irradiation angle cannot be changed.
Therefore, straight fiber illumination must be used. However, when measuring a cylindrical object to be measured, illumination unevenness may occur.

In the prior art 5, since the irradiation angle is uniquely determined from the diameter of the objective lens and the like, there is a problem that the irradiation angle cannot be changed. Further, in the conventional example 6, since the Fresnel lens is fixed, there is a problem that the irradiation angle cannot be changed as in the conventional example 5.

An object of the present invention is to provide an illuminating device for an optical measuring instrument which solves such a conventional problem, has a simple structure, and can easily change an irradiation angle on an object to be measured. It is in.

[0012]

Therefore, according to the present invention, the illumination light from the light generating means is refracted by a condensing lens and condensed on the optical axis, and the condensing lens is moved along the optical axis. In this case, the object is achieved by changing the irradiation angle. Specifically, the illumination device for an optical measurement device of the present invention is a light generation unit that generates illumination light radially outward around the optical axis of the optical system, and concentric with the optical axis of the optical system, and An illumination angle varying means for converging illumination light from the light generating means toward the object to be measured, wherein the illumination angle varying means comprises: A light-condensing lens is provided, which refracts illumination light and condenses it on the optical axis, and is movable along the optical axis.

In the present invention having this configuration, the illumination light generated from the light generating means is radiated to the object to be measured by the condenser lens constituting the irradiation angle changing means. Here, when changing the irradiation angle of the illumination light to the object to be measured, the condenser lens is moved along the optical axis. For example, in order to reduce the irradiation angle of the illumination light applied to the object to be measured, a condenser lens is placed at a position close to the light generating means. Then, the illumination light generated by the light generation means is refracted at the central portion of the condenser lens and is irradiated on the object at a small angle. On the other hand, in order to increase the irradiation angle, the condenser lens is placed at a position separated from the light generating means. Then, the illumination light generated by the light generating means is refracted at the peripheral portion of the condenser lens and is irradiated on the measured object at a large angle. Therefore, the irradiation angle changing means has a simple configuration of a condenser lens, and the irradiation angle of the illumination light can be easily changed by moving the condenser lens along the optical axis.

Here, in the present invention, the condenser lens may be an annular lens. In this configuration, the illumination light reflected by the object to be measured is observed by the optical system through the optical axis of the optical system without being blocked by the annular lens, so that appropriate measurement can be ensured. Further, the condenser lens may be composed of a plurality of lenses. By arranging these condenser lenses along the optical axis and adjusting their relative distances, it is possible to finely adjust the irradiation angle on the object to be measured.

The light generating means may include a ring-shaped fiber illumination centered on the optical axis, or a ring-shaped LED illumination centered on the optical axis. Configuration. In these configurations, the light amount can be adjusted and the irradiation position can be easily changed by selectively turning on / off the fiber lighting or the LED lighting.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a lighting device according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same components will be denoted by the same reference numerals, and the description thereof will be omitted or simplified. [First Embodiment] A first embodiment is shown in FIGS. FIG. 1 shows an example in which the present invention is applied to an image processing type measuring instrument. The image processing type measuring apparatus 10 is roughly composed of a microscope 20 and an image display device 90.

The microscope 20 has a horizontal portion 21A and an upright portion 2A.
1B includes a side L-shaped support base 21 having 1B. Support stand 2
On the one horizontal portion 21A, a mounting table 22 on which the DUT 25 is mounted is provided on the upper surface. The mounting table 22 is movable in X-axis directions orthogonal to each other in a horizontal plane, that is, in the horizontal direction (X-axis direction) and the front-rear direction (Y-axis direction)
A Y-table, and the amount of movement in each axis direction can be set or measured by the X-axis micrometer head 23 and the Y-axis micrometer head 24.

A vertical guide 27 having a vertical knob 26 is provided on the upright portion 21B of the support base 21.
On the up / down guide 27, a side U-shaped support frame 31 that moves up and down via a rack, a pinion, or the like (not shown) is pivotably supported by a turning operation of the up / down knob 26. On the open front side of the support frame 31, cylindrical bodies (not shown) are respectively interposed at the left and right ends thereof, and a flat U-shaped cover 33 is provided on the open side of the support frame 31.
Is attached.

An imaging optical system 37 is provided at the center of the support frame 31.
Is provided. As shown in FIG. 2, the imaging optical system 37 includes an objective lens 34 protruding below the support frame 31,
The imaging lens 3 provided coaxially with the objective lens 34
5 and a CCD camera 36 provided coaxially with the imaging lens 35 and protruding above the support frame 31. An image display device 90 is connected to the CCD camera 36 via a wiring cord 38.

An illumination device 40 for an optical measuring instrument according to the present embodiment is provided below the support frame 31. The illumination device 40 for an optical measuring device includes a ring-shaped light generation unit 41 that generates illumination light radiating outward around the optical axis of the imaging optical system 37, and concentric with the optical axis of the imaging optical system 37. ,And,
An irradiation angle varying unit 42 for condensing the illumination light from the light generation unit 41 toward the object 25 to be measured is provided.

The light generating means 41 includes a fiber illuminator 51 which emits illumination light in a ring shape with the optical axis as the center and radiates downward and outward, a cylindrical member 43 for attaching the fiber illuminator 51 to the support frame 31, and It has. The cylindrical member 43 and the fiber illumination 51 are arranged coaxially with the optical axis, and the inner peripheral surface thereof and the objective lens 34 are arranged.
A gap having a predetermined size is formed between the outer peripheral surface and the outer peripheral surface.

As shown in FIG. 3, the fiber illumination 51 includes a ring-shaped member 52 having an annular space therein, and a plurality of optical fibers 53 housed in a state of being bundled in the annular space of the ring-shaped member 52. It is composed of The distal end 53A of each optical fiber 53 is connected to the ring-shaped member 5 one by one.
2 are arranged in a ring shape obliquely downward. The proximal end 53B of each optical fiber 53 is guided to a light source (not shown). The fiber illumination 51 is configured so that illumination light can be partially generated by selectively turning on / off each optical fiber 53.

The irradiation angle varying means 42 is a single condenser lens 44 for refracting the illumination light from the light generating means 41 and condensing it on the optical axis, and manually moving the condenser lens 44 along the optical axis. Or, a moving mechanism (not shown) for automatically moving up and down is provided. The condensing lens 44 is an annular lens whose axis coincides with the optical axis. In order to prevent the converging lens 44 from interfering with the objective lens 34,
The inner diameter is formed larger than the outer diameter of the objective lens 34. The condenser lens 44 is composed of various lenses such as an aspherical surface, an ellipse, a parabola, and a Fresnel, but the type is not limited as long as it can collect illumination light on the optical axis.

The image display device 90 includes a CRT 91 and a CC
And a control device 92 for displaying a signal from the D camera 36 on the CRT 91. The control device 92 includes an operation unit 93 including knobs, switches, and the like for performing the above-described respective controls at a front portion thereof.

Next, the operation of the first embodiment will be described with reference to FIG. In the measurement, the X-axis and Y-axis micrometer heads 2 of the stage 22 are placed such that the object 25 placed on the stage 22 faces the objective lens 34.
Turn 3, 24 to set. In addition, vertical movement knob 2
6 is set so that the measurement site of the DUT 25 is located at the focal position of the objective lens 34.

In this state, as shown in FIG.
The light emitted from the fiber illumination 51 of the light generation means 41 at a spread angle α from the optical axis is condensed by the condenser lens 44 and is irradiated on the object 25 to be measured. Light reflected from the device under test 25 is incident on a CCD camera 36 via an objective lens 34 and an imaging lens 35. Here, after being converted into an electric signal, it is input to the control device 92 of the image display device 90. As a result, an image of the DUT 25 is displayed on the CRT 91.

Here, when changing the irradiation angle of the illumination light to the object 25 to be measured, the condenser lens 44 is moved along the optical axis by a moving mechanism (not shown). For example, in order to reduce the irradiation angle β of the illumination light applied to the object 25, the condenser lens 44 is placed at a position close to the fiber illumination 51 of the light generation unit 41, as shown by the solid line in FIG. Then, the illumination light generated by the fiber illumination 51 is
The light is refracted at the central portion of the condenser lens 44 and is irradiated on the object 25 at a small angle. On the other hand, to increase the irradiation angle β, the condenser lens 44 is placed at a position separated from the fiber illumination 51 as shown by the imaginary line in FIG.
Then, the illumination light generated by the fiber illumination 51 is refracted by the peripheral edge of the condenser lens 44 and illuminates the DUT 25 at a large angle. The adjustment of the amount of illumination light and the adjustment of the irradiation position are performed by selectively turning on and off the fiber illumination 51.

Therefore, according to the first embodiment, the irradiation angle changing means 42 for condensing the illumination light from the light generating means 41 toward the object 25 is an optical member having a simple structure such as a condenser lens 44. The condenser lens 4
4 can be moved along the optical axis of the imaging optical system 37, so that the irradiation angle of the illumination light to the object 25 can be easily changed. Therefore, the illumination light can be emitted at an appropriate angle in accordance with the shape of the edge of the DUT 25, and the image of the edge of the DUT 25 can be drawn clearly without impairing the stereoscopic effect. .

Further, since the converging lens 44 is an annular lens whose axis coincides with the optical axis of the imaging optical system 37, the illumination light reflected on the object 25 is not blocked by the converging lens 44. Since the image is observed by the imaging optical system 37 through the optical axis, proper measurement can be ensured. Further, since the light generating means 41 has a configuration including the fiber illumination 51 formed in a ring shape with the optical axis of the imaging optical system 37 as the center, the fiber illumination 51 is selectively turned on and off. Light amount adjustment and irradiation position can be easily changed.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment is different from the first embodiment in that the light generating means 141 is different from the light generating means 41 of the first embodiment. In FIG. 5, an illumination device 140 for an optical measurement device according to the present embodiment is provided below the support frame 31 of the microscope 20. The optical measuring instrument illumination device 140 includes a ring-shaped light generating unit 141 that generates outwardly radiating illumination light with the optical axis of the imaging optical system 37 as a center, and concentric with the optical axis of the imaging optical system 37. Irradiation angle variable means 4 arranged
2 is provided.

The light generating means 141 has a ring shape around the optical axis and emits illuminating light downward and outward.
And a cylindrical member 43 attached to the first member. The cylindrical member 43 and the LED lighting 151 are arranged coaxially with the optical axis, and a gap of a predetermined size is formed between the inner peripheral surface and the outer peripheral surface of the objective lens 34. .

The LED lighting 151 includes a ring-shaped frame 152 and a plurality of light emitting elements 153 arranged inside the frame 152. The light emitting elements 153 are arranged in a ring shape obliquely downward from the frame 152. The LED lighting 151 is provided for each light emitting element 1
53 is a configuration in which illumination light can be partially generated by selectively turning on and off.

Next, the operation of the second embodiment will be described with reference to FIG. In the measurement, as in the first embodiment, the object 25 placed on the stage 22 is set so as to face the objective lens 34, and the objective lens 34 is set.
Is set so that the measurement site of the DUT 25 is located at the focal position of. In this state, as shown in FIG. 6, the light emitted from the LED illumination 151 of the light generation means 141 at the spread angle α from the optical axis is collected by the condenser lens 44.
And irradiates the object 25 to be measured.

Here, when changing the irradiation angle of the illumination light to the object 25 to be measured, similarly to the first embodiment, the condenser lens 44 is moved along the optical axis by a moving mechanism (not shown). For example, in order to reduce the irradiation angle β of the illumination light applied to the DUT 25, the condenser lens 44 is placed at a position close to the LED illumination 151 of the light generation unit 141 as shown by a solid line in FIG. Then, the illumination light generated by the LED illumination 151 is refracted at the central portion of the condenser lens 44 and irradiates the DUT 25 at a small angle.

On the other hand, in order to increase the irradiation angle β, as shown by an imaginary line in FIG.
It is placed at a position separated from the ED lighting 151. Then, LE
The illumination light generated by the D illumination 151 is refracted at the peripheral edge of the condenser lens 44 and is applied to the DUT 25 at a large angle. Adjustment of the amount of illumination light and adjustment of the irradiation position are performed using LEDs.
This is performed by selectively turning on and off the lighting 151.

Therefore, according to the second embodiment, the operation and effect of the first embodiment can be obtained. Further, since the light generating means 141 has a configuration including the LED lighting 151 formed in a ring shape around the optical axis of the imaging optical system 37, the same operation and effect as those of the first embodiment are achieved. That is, by selectively turning on / off the LED lighting 151, the light amount adjustment and the irradiation position can be easily changed.

[Third Embodiment] Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the light generating means 241 is different from the light generating means 4 of the first and second embodiments.
1 and 141, and other configurations are the same as those of the first and second embodiments. In FIG. 7, an illumination device 240 for an optical measurement device according to the present embodiment is provided below the support frame 31 of the microscope 20.

The optical measuring instrument illuminating device 240 collects the illumination light from the light generating means 41 toward the DUT 25 concentrically with the optical axis of the imaging optical system 37 and the light from the light generating means 41. And an irradiation angle varying means 242 for emitting light. The irradiation angle varying means 242 is
A plurality of (two in the figure) condenser lenses 44 for refracting the illumination light from the lens and condensing them on the optical axis, and manually or automatically moving these condenser lenses 44 up and down along the optical axis, respectively. And a moving mechanism (not shown) for moving. These condensing lenses 44 are arranged vertically one above the other such that the axis thereof coincides with the optical axis.

Next, the operation of the third embodiment will be described with reference to FIG. In the measurement, as in the first embodiment, the object 25 placed on the stage 22 is set so as to face the objective lens 34, and the objective lens 34 is set.
Is set so that the measurement site of the DUT 25 is located at the focal position of. In this state, as shown in FIG. 8, light emitted from the fiber illumination 51 of the light generating means 41 at a spread angle α from the optical axis is condensed by the two condensing lenses 44 and Irradiated.

Here, when changing the irradiation angle of the illumination light on the object 25, the two condenser lenses 44 are synchronously moved or differentially moved along the optical axis by a moving mechanism (not shown). For example, in order to reduce the irradiation angle β of the illumination light applied to the device under test 25, as shown by the solid line in FIG. Put on. Then, the illumination light generated by the fiber illumination 51 is refracted at the central portions of the two condenser lenses 44 and irradiates the DUT 25 at a small angle.

On the other hand, in order to increase the irradiation angle β, as shown by imaginary lines in FIG.
4 is placed away from the fiber light 51. Then, the illumination light generated by the fiber illumination 51 is refracted by the peripheral portion of the condenser lens 44 and becomes a large angle at the object 25 to be measured.
Is irradiated.

Therefore, according to the third embodiment, the same operation and effect as those of the first embodiment can be obtained. In addition, since a plurality of condenser lenses 44 are used, these condenser lenses 44 can be used. By arranging them along the optical axis and adjusting their relative distances, fine adjustment of the irradiation angle to the DUT 25 can be performed. In the third embodiment, an LED illumination 151 may be used instead of the fiber illumination 51.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. Is possible. For example,
In each of the above embodiments, the condenser lens 44 is an annular lens. However, in the present invention, if the light reflected from the DUT 25 is transmitted to the imaging optical system 37, the axial core is integrated with the peripheral edge. Alternatively, it may be composed of ordinary lenses. Further, the light generating means 41 and 141 use optical fibers or LEDs, but lasers or the like can be used.

The illumination device for an optical measuring device according to the present invention is not limited to a tool microscope, but can be applied to other types of optical measuring devices such as a projector and a three-dimensional measuring device. It is.

[0045]

As described above, according to the present invention, it is possible to achieve an effect that the structure is simple and the irradiation angle to the object to be measured can be easily changed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a tool microscope to which a first embodiment of the present invention is applied.

FIG. 2 is a sectional view showing a main part of the first embodiment.

FIG. 3 is a top perspective view of the fiber illumination according to the first embodiment.

FIG. 4 is a schematic configuration diagram for explaining an operation of the first embodiment.

FIG. 5 shows a main part of a second embodiment of the present invention, and FIG.
FIG.

FIG. 6 is a schematic configuration diagram for explaining the operation of the second embodiment.

FIG. 7 shows a main part of a third embodiment of the present invention, and FIG.
FIG.

FIG. 8 is a schematic configuration diagram for explaining the operation of the third embodiment.

[Explanation of symbols]

 25 Object to be measured 37 Optical system 40,140,240 Illumination device for optical measuring instrument 41,141 Light generation means 42,242 Irradiation angle variable means 44 Condenser lens 51 Fiber illumination 151 LED illumination

Claims (5)

[Claims] 1. A light generating means for generating illumination light radially outward around an optical axis of an optical system, and receiving illumination light from the light generating means concentric with the optical axis of the optical system. An illumination device for an optical measuring device, comprising: an irradiation angle varying unit that converges light toward the measurement object, wherein the irradiation angle varying unit refracts the illumination light from the light generation unit on the optical axis. An illuminating device for an optical measurement device, comprising: a condensing lens that converges light and is movable along the optical axis. 2. The illumination device for an optical measurement device according to claim 1, wherein the condenser lens is an annular lens. 3. The illumination device for an optical measurement device according to claim 1, wherein the condenser lens is composed of a plurality of lenses. 4. An illumination device for an optical measuring instrument according to claim 1, wherein said light generating means includes a ring-shaped fiber illumination centered on said optical axis. Characteristic lighting equipment for optical measuring instruments. 5. The illumination device for an optical measuring device according to claim 1, wherein the light generating means includes a ring-shaped LED illumination centered on the optical axis. Characteristic lighting equipment for optical measuring instruments.